Filter effects and Raw images

Can someone clarify the situation re applying filter effects and raw images when shooting digitally on my Canon EOS 5D.

In the situation of wanting to say apply the equivalent of a red filter to a landscape which is ultimately to be rendered in black and white, do I apply the red filter to a colour image, and convert to B&W in Photoshop, or to a an in camera monochrome version? Does the application of the red filter make any difference to the raw image ( I assume not since by definition raw images are 'pure ' sensor images), or should I capture such images in JPEG format? I ask this because I have tried applying a red filter to images, and I do not seem to get the same darkening of skies as in film photography.
Cheers
jwillyf

I didn't mention the option of physically applying a red filter in front of the camera lens!
Any feedback appreciated
jwillyf

Don't use "photo filters" in PS if your plan is to convert to B&W, you can play a lot more in the Channel Mixer feature, just check the "monochrome" box.

I have tried using both yellow and red filters on my 10D, thinking that I'd get better exposure of yellows, reds, and greens... but it didn't work. I don't have the test shots anymore, but try it yourself and I think you'll see it's easier to use channel mixer in PS.

-Mark

Mark,

That seems to be my experience too - that filters in front of lens on the 5D, or using the 5D in camera filters just do not work in the same way as film in 'conventional' cameras.
Is that others' experience too?
jwillyf